Z-Directed Variable Value Components for Printed Circuit Boards

ABSTRACT

A Z-directed variable value component for insertion into a printed circuit board while allowing electrical connection to internal conductive planes contained with the PCB. The Z-directed variable value component mounts in a printed circuit board (PCB) having a mounting hole having a depth D therein and a plurality of conductive traces and comprises an insulative body of a length L comprising a top surface; a bottom surface; a side surface between the top and bottom surfaces; a cross-sectional shape that is insertable into the mounting hole in the PCB; and a first and a second electrically conductive channels on the side surface with the first channel and second channel both extending from one of the top and bottom surfaces; a plateable strip disposed on the side surface intermediate the top and bottom surfaces; and a first and second conductor disposed within the body, the first conductor electrically connected to the first channel and one end of the plateable strip and the second conductor electrically connected to the second channel and the other end of the plateable strip. In one form the plateable strip is comprised of a resistive material. In another form the plateable strip is comprised of a material having an electrical characteristic that changes when plating is applied to the strip after installation of the Z-directed component in the mounting hole of the PCB.

CROSS REFERENCES TO RELATED APPLICATIONS

This patent application is related to U.S. patent application Ser. No.______ (Attorney Docket No. 2008-0295.01) entitled “Z-directedComponents for Printed Circuits Boards”; Ser. No. ______ (AttorneyDocket No. 2009-0117.00) entitled “Z-directed Pass-Through Componentsfor Printed Circuits Boards”; Ser. No. ______ (Attorney Docket No.2009-0118.00) entitled “Z-directed Capacitor Components for PrintedCircuits Boards”; Ser. No. ______ (Attorney Docket No. 2009-0119.00)entitled “Z-directed Delay Line Components for Printed Circuits Boards”;Ser. No. ______ (Attorney Docket No. 2009-0120.00) entitled “Z-directedFilter Components for Printed Circuits Boards”; Ser. No. ______(Attorney Docket No. 2009-0121.00) entitled “Z-directed Ferrite BeadComponents for Printed Circuits Boards”; Ser. No. ______ (AttorneyDocket No. 2009-0122.00) entitled “Z-directed Switch Components forPrinted Circuits Boards”; Ser. No. ______ (Attorney Docket No.2009-0123.00) entitled “Z-directed Connector Components for PrintedCircuits Boards”; each filed MONTH DAY, 2009 and all assigned to theassignee of the present application.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

None.

REFERENCE TO SEQUENTIAL LISTING, ETC.

None.

BACKGROUND

1. Field of the Invention

The present invention relates electronic components, and moreparticularly to those for insertion into a printed circuit board andmethods of assembly.

2. Description of the Related Art

Printed Circuit Board (PCB) manufacturing primarily uses two types ofcomponents. The first type is pin through-hole parts that use metallicleads that are soldered into a plated through-hole in the PCB. Thesecond type of component is a surface mount part that sits on thesurface of a PCB and it attached by soldering to pads on the surface. Asdensities of components have increased and higher frequencies ofoperation are used, some circuits' designs have become very difficult toachieve. The presented invention improves the component densities andfrequencies of operation.

Currently resistors can be embedded between layers of a PCB by applyinga resistive material between two copper traces after the etching step inthe manufacturing process. A typical 4 layer PCB is made up of twoassemblies that are each two layer PCBs. These are glued together with amaterial to become the completed assembly. The resistive area can beapplied to any layer making it possible to have the resistive elementson the interior layers. However this approach is more time consuming andmakes changes difficult to implement. The present invention removesthese difficulties by allowing for insertion of the part to occur afterthe multilayered PCB is assembled.

SUMMARY OF THE INVENTION

A Z-directed component for mounting in a printed circuit board (PCB)having a mounting hole having a depth D therein and a plurality ofconductive traces, the Z-directed component comprises an insulative bodyof a length L comprising a top surface; a bottom surface; a side surfacebetween the top and bottom surfaces; a cross-sectional shape that isinsertable into the mounting hole in the PCB; and a first and a secondelectrically conductive channels on the side surface with the firstchannel and second channel both extending from one of the top and bottomsurfaces; a plateable strip disposed on the side surface intermediatethe top and bottom surfaces; and a first and second conductor disposedwithin the body, the first conductor electrically connected to the firstchannel and one end of the plateable strip and the second conductorelectrically connected to the second channel and the other end of theplateable strip. In one form the plateable strip is comprised of aresistive material. In another form the plateable strip is comprised ofa material having an electrical characteristic that changes when platingis applied to the strip after installation of the Z-directed componentin the mounting hole of the PCB. In another form the strip is a metallicstrip that is etched away to achieve variability in the value of thecomponent.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features and advantages of the variousembodiments of the invention, and the manner of attaining them, willbecome more apparent will be better understood by reference to theaccompanying drawings, wherein:

FIG. 1 is an illustration of one embodiment of a Z-directed component;

FIG. 2 is an illustrates the internal arrangement of elements comprisingone embodiment of the Z-directed component of FIG. 1;

FIGS. 3A-3F illustrate various shapes for the body of a Z-directedcomponent;

FIGS. 4A-4C illustrate various channel configurations for a Z-directedcomponent;

FIGS. 5A-5H illustrate various channel and conductor configurations forthe body of a Z-directed component;

FIGS. 6A-6D illustrate various orienting locating or connection featuresof a Z-directed component;

FIGS. 7A and 7B illustrate a Z-directed component having O-rings forconnecting to internal layers of a PCB and having a body having regionscomprised of similar and or dissimilar materials;

FIG. 8 illustrates various elements or electronic components such as aresistor, diode, capacitor that may be provided within the body of aZ-directed component in series with a conductor;

FIG. 9 illustrates a Z-directed component having a 3-terminal transistorconnected to two conductors;

FIG. 10 illustrates an alternate embodiment of a Z-directed componenthaving a 3-terminal transistor connected to a conductor and a platedchannel;

FIG. 11 illustrates a cross-sectional view of the embodiment of aZ-directed component flush mounted within a PCB shown in FIG. 12;

FIG. 12 illustrates a top view of the PCB and the Z-directed componentof FIG. 11 showing the conductive traces and connections to theZ-directed component;

FIG. 13 illustrates ground loops for the Z-directed component of FIGS.11 and 12 with the Z-directed component further comprising with adecoupling capacitor within the body of the Z-directed component;

FIG. 14 is an illustration of a Z-directed component for transferring asignal trace from one internal layer of a PCB to another internal layerof that PCB;

FIG. 15 is an illustration of one embodiment of a Z-directed capacitorcomprising semi-cylindrical sheets;

FIG. 16 is an exploded view illustration of another embodiment of aZ-directed capacitor comprising stacked discs;

FIGS. 17A-17C illustrate alternate embodiments of a Z-directed delayline with transparent surfaces to display connections;

FIG. 18 illustrates a programmable Z-directed delay line circuit havingmultiple Z-directed delay lines with transparent surfaces to displayconnections;

FIGS. 19A-19C illustrate sectional views of a single conductordifferential Z-directed ferrite bead, a 2 conductor differential modeZ-directed ferrite bead, and a 2 conductor common mode Z-directedferrite bead;

FIGS. 20A and 20B illustrate a Z-directed switch component that can berotated to connect predetermined circuit paths in a PCB;

FIG. 20B is a sectional illustration of the PCB taken along line 20B-20Bof FIG. 19A with the Z-directed switch component removed to showinternal connection points of the PCB;

FIG. 20C is an illustration of the Z-directed switch component of FIG.20A having an internal electronic component;

FIG. 20D is a top view of the Z-directed switch component of FIG. 20Cshowing alternate configurations of the channel shapes and conductivemember and radial projections;

FIGS. 21A-21D illustrate a Z-directed component utilized for makinginternal connections between traces on different internal layers orbetween traces on a given internal layer of a PCB along with anadditional feature of a testing path for checking the connections;

FIGS. 22A and 22B illustrate the use of a plateable side strip andpartial insertion of Z-directed components to alter value or function ofthe Z-directed component;

FIG. 23 is an illustration of a system for inserting Z-directedcomponents into a PCB;

FIG. 24 is an illustration of a Z-directed component having a glue stripand a glue dot for mounting of the Z-directed component in a PCB; and

FIG. 25 is an illustration of a Z-directed component showing copper seedmaterial and resist material used when plating a Z-directed component.

DETAILED DESCRIPTION

The present invention will now be described more fully hereinafter withreference to the accompanying drawing figures, in which some, but notall embodiments of the invention are shown. It is to be understood thatthe invention is not limited in its application to the details ofconstruction and the arrangement of components set forth in thefollowing description or illustrated in the drawings. The invention maybe embodied in many different forms and should not be construed aslimited to the embodiments set forth herein; rather, these embodimentsare provided so that this disclosure will satisfy applicable legalrequirements.

The phraseology and terminology used herein is for the purpose ofdescription and should not be regarded as limiting. The use of“including,” “comprising,” or “having” and variations thereof herein ismeant to encompass the items listed thereafter and equivalents thereofas well as additional items. Unless limited otherwise, the terms“connected,” “coupled,” and “mounted,” and variations thereof herein areused broadly and encompass direct and indirect connections, couplings,and mountings. In addition, the terms “connected” and “coupled” andvariations thereof are not restricted to physical or mechanicalconnections or couplings.

As described in subsequent paragraphs, the specific mechanicalconfigurations illustrated in the drawings are intended to exemplifyembodiments of the invention and that other alternative mechanicalconfigurations are possible.

This specification describes a family of components that are intended tobe embedded or inserted into a printed circuit board (PCB). Thesecomponents are termed Z-directed components and have been modeled andbasic prototypes of many of the components described herein, but lackingthe surface channels, were made to establish proof of concept. Not allembodiments described herein have been constructed. An overview of howZ-directed components are intended to be formed is presented initiallyfollowed by configurations for Z-directed component designs includingbut not limited to capacitors, delay lines, transistors, switches, andconnectors. This is followed by techniques believed to be useful forassembling PCBs with Z-directed components. Z-directed components occupyless space on the surface of a PCB and for high frequency circuits (e.g.clock rates greater than 1000 MHz) allow for higher frequency ofoperation.

Overview

As used here in an X-Y-Z frame of reference is used. The X and Y axesdescribe the plane of a printed circuit board. The Z-axis describes adirection perpendicular to the plane of the circuit board. The topsurface of the PCB has a zero Z-value. A component with a negativeZ-direction value indicates that the component is inserted into the topsurface of the PCB. Such a component may be above (extend past), flushwith, or recessed below either the top surface and/or the bottom surfaceof the PCB. A component having both a positive and negative Z-directionvalue indicates that the component is partially inserted into thesurface of the PCB. Z-directed components are intended to be insertedinto a hole or recess in a printed circuit board. Depending on its shapeand length more than one Z-directed component may be inserted into asingle mounting hole in the PCB, such as being stacked together orpositioned side by side. The hole may be a through hole (a hole from thetop surface through to the bottom surface) or a well (a opening orrecess through either the top or bottom surface into an interior portionor internal layer of the PCB.

As described herein the Z-directed components are illustrated as beinginserted into the top surface of the PCB. For a PCB having conductivetraces on both external layers, one external layer is termed the topsurface and the other the bottom surface. Also where only one externallayer has conductive traces, that external surface is referred to as thetop surface. The Z-directed component are referred to as having a topsurface, a bottom surface and a side surface. The references to top andbottom surfaces of the Z-directed component conform to the conventionused to refer to the top and bottom surfaces of the PCB. The sidesurface of a Z-directed component is in the Z-direction and would beadjacent to the wall of the mounting hole in the PCB which is also inthe Z-direction. This use of top, bottom and side should not be taken aslimiting how a Z-directed component may be mounted into a PCB. Althoughthe components are described herein as being mounted in a Z-direction,this does not mean that such components are limited to being insertedinto a PCB only along the Z-axis. Z-directed components may be mountednormal to the plane of the PCB from the top or bottom surfaces or bothsurfaces, mounted at an angle thereto or, depending on the thickness ofthe PCB and the dimensions of the Z-directed component and even insertedinto the edge of the PCB between to the top and bottom surfaces of thePCB.

The Z-directed components may be made from various combinations ofmaterials commonly used in electronic components. The signal connectionpaths will be made from conductors which are materials that have highconductivity. Conducting materials include, but are not limited to,copper, gold, aluminum, silver, tin, lead and many others. Z-directedcomponents will have areas that need to be insulated from other areas byusing materials that have low conductivity like plastic, glass, FR4(epoxy & fiberglass), air, mica, ceramic and others. A Z-directedcomponent that is constructed as a resistor requires materials that haveproperties that are between a conductor and insulator which have afinite amount of resistivity which is the reciprocal of conductivity.Materials like carbon, doped semiconductor, nichrome, tin-oxide andothers are used for their resistive properties. Capacitors are typicallymade of two conducting plates separated by an insulating material thathas a high permittivity (dielectric constant). Permittivity is aparameter that shows the ability to store electric fields in thematerials like ceramic, mica, tantalum and others. Inductors aretypically made of coils of wires or conductors wrapped around a materialwith high permeability. Permeability is a parameter that shows theability to store magnetic fields in the material which are iron andalloys like nickel-zinc, manganese-zinc, nickel-iron and others.Transistors and FET are electronic devices that are made fromsemiconductors that behave in a nonlinear fashion and are made fromsilicon, germanium, gallium arsenide and others. Throughout theapplication there are references that discuss different materials,properties of materials or terminology interchangeably as currently usedin the art of material science and electrical component design. Becauseof the flexibility in how a Z-directed component is constructed and thenumber of materials that may be used, it is also contemplated thatZ-directed components may be constructed of materials that have not beendiscovered or created to date. The body of a Z-directed component willin general be comprised of a non-conductive material unless otherwisecalled out in the description for a particular design of a Z-directedcomponent such as a capacitor.

The PCB which use a Z-directed component may be constructed to have asingle conductive layer or multiple conductive layers as is known. ThePCB may have conductive traces on the top surface only, on the bottomsurface only, on both the top and bottom surfaces. In addition one ormore intermediate internal conductive trace layers may also be presentin the PCB.

Connections between a Z-directed component and the traces in or on a PCBmay be accomplished by soldering techniques, screening techniques,extruding techniques or plating techniques as are known in the art.Depending upon application, solder pastes and component adhesives may beused. In some configurations, compressive conductive members may be usedto interconnect a Z-directed component to conductive traces found on thePCB.

Z-directed Components

The most general form a Z-directed component comprises a body having atop surface, a bottom surface and a side surface, a cross-sectionalshape that is insertable into a mounting hole of a given depth D withina PCB with a portion of the body comprising an insulator. All of theembodiments described herein for Z-directed components are based on thisgeneral form.

FIGS. 1 and 2 show an embodiment of a Z-directed component. ThereZ-directed component 10 comprises a generally cylindrical body 12 havinga top surface 12 t, a bottom surface 12 b, a side surface 12 s, and alength L generally corresponding to the depth D of the mounting hole.The length L can be less than, equal to or greater than the depth D. Inthe former two cases, Z-directed component 10 would in one case be belowat least one of the top and bottom surfaces of the PCB and in the otherit would be flush with the two surfaces of the PCB. Where length L isgreater than depth D, Z-directed component 10 would not be flushmounted. However with this non-flush mount, Z-directed component 10would be capable of being used to interconnect to another component oranother PCB that is positioned nearby. The mounting hole is typically athrough-hole extending between the top and bottom surfaces of the PCBbut it may also be a blind hole. When recessed below the surface of thePCB additional resist areas may be required in the hole of the PCB tokeep from plating the entire circumferential area around the hole.

Z-directed component 10 in one form may have at least one conductor 14extending through the length of body 12. At the top and bottom ends 14 tand 14 b of conductor 14 top and bottom conductive traces 16 t, 16 b areprovided on the top and bottom end surfaces 12 t, 12 b of body 12 andextend from respective ends of the conductor 14 to the edge ofZ-directed component 10. In this embodiment body 12 comprises anon-conductive material. Depending on its function, body 12 ofZ-directed component 10 may be made of variety of materials havingdifferent properties. These properties include being conductive,resistive, magnetic, dielectric, or semiconductive or variouscombinations of properties as described herein. Examples of materialsthat have the properties are copper, carbon, iron, ceramic or silicon,respectively. Body 12 of Z-directed component 10 may also comprise anumber of different networks needed to operate a circuit that will bediscussed later.

One or more longitudinally extending channels or wells may be providedon the side surface of body of Z-directed component 10. The channel mayextend from one of the top surface and the bottom surface of body 12toward the opposite surface. As illustrated two concave wells orchannels 18 and 20 are provided in the outer surface of Z-directedcomponent 10 extending the length of body 12. When plated or soldered,these channels allow electrical connections to be made to Z-directedcomponent 10, through the PCB, as well as to internal conductive layerswithin the PCB. The length of the channels 18 or 20 may extend less thanthe entire length of body 12.

FIG. 2 shows the same component as in FIG. 1 but with all the surfacestransparent. The conductor 14 is shown as a cylinder extending throughthe center of Z-directed component 10. Other shapes may also be used forconductor 14. Traces 16 t and 16 b can be seen extending from conductorends 14 t and 14 b, respectively to the edge of body 12 is a conductorthat connects the top trace 16 t to the bottom trace 16 b. While traces16 t and 16 b are shown as being in alignment with one another ( zerodegrees apart) this is not a requirement and they may be positioned asneeded for a particular design. For example traces 16 t and 16 b may be180 degrees apart or 90 degrees apart and any all increments therein.

Body shape may be any shape that can fit into a mounting hole in a PCB.FIGS. 3A-3F illustrate possible body shapes for a Z-directed component.FIG. 3A shows a triangular cross-sectional body 40; FIG. 3B arectangular cross sectional body 42; FIG. 3C a frusto-conical body 44;FIG. 3D a ovate cross sectional cylindrical body 46; and FIG. 3E acylindrical body 48. FIG. 3F is a stepped cylindrical body 50 where oneportion 52 has a larger diameter than another portion 54. With thisarrangement the Z-directed component may be mounted on the surface ofthe PCB while having a section being inserted into a the mounting holeprovided in the PCB. The edges of Z-directed component may be beveled tohelp with aligning the Z-directed component for insertion into athrough-hole in a PCB. Other shapes and combinations of thoseillustrated may also be used for a Z-directed component.

For a Z-directed component, the channels for plating can be of variouscross-sectional shapes and lengths. The only requirement is that platingor solder material make the proper connections to the Z-directedcomponent and corresponding conductive traces in or on the PCB. Channels18 or 20 may have, for example, V-, C- or U-shaped cross sections,semi-circular or elliptical cross sections. Where more than one channelis provided, each channel may have a different cross-sectional shape.FIGS. 4A-4C illustrate three channel shapes. In FIG. 4A V-shapedchannels 60 are shown. In FIG. 4B, U- or C-shaped channels 62 are shown.In FIG. 4C, wavy or irregular cross-sectional channel shapes 65 areshown.

The numbers of layers in a PCB varies from being single sided to beingover 22 layers and may have different overall thickness that range fromless than 0.051 inch to over 0.093 inch or more. Where a flush mount isdesired the length of the Z-directed component will depend on of thethickness of the PCB into which is intended to be inserted. TheZ-directed component's length may also vary depending of the intendedfunction and tolerance of a process. The preferred lengths will be wherethe Z-directed component is either flush the surfaces or extendsslightly beyond the surface of the PCB. This would keep the platingsolution from plating completely around the interior of the PCB holethat may cause a short in some cases. It is possible to add a resistmaterial around the interior of a PCB hole to only allow plating in thedesired areas. However, there are some cases where it is desired tocompletely plate around the interior of a PCB hole above and below theZ-directed component. For example if the top layer of the PCB was a Vccplane and the bottom layer is a GND plane then a decoupling capacitorwould have lower impedance if the connection used a greater volume ofcopper to make the connection.

There are number of features that can be added to a Z-directed componentto create different mechanical and electrical characteristics. Thenumber of channels or conductors can be varied from zero to any numberthat can maintain enough strength to take the stresses of insertion,plating, manufacturing processes and operation of the PCB in itsintended environment. The outer surface of a Z-directed component mayhave a coating that glues it in place. Flanges or radial projections mayalso be used to prevent over or under insertion of a Z-directedcomponent into the mounting hole, particular where the mounting hole isa through-hole. A surface coating material may also be used to promoteor impede migration of the plating or solder material.

A Z-directed component may take on several roles depending on the numberof ports or terminals needed to make connections to the PCB. Somepossibilities are shown in FIGS. 5A-H. FIG. 5A is a Z-directed componentconfigured as 0-port device 70A used as a plug so that if a filter or acomponent is optional then the plug stops the hole from being plated.After the PCB has been manufactured, the 0-port device 70A may beremoved and another Z-directed component may be inserted, plated andconnected to the circuit. FIGS. 5B-5H illustrates various configurationsuseful for multi-terminal devices such as resistor, diode, transistor,clock circuit. FIG. 5B shows a 1-port or single signal Z-directedcomponent 70B having a conductor 71 connected to top and bottomconductive traces 72 t, 72 b. FIG. 5C shows a 1-port 1-channelZ-directed component 70C where one plated well or channel 73 is providedin addition to conductor 71 and top and bottom conductive traces 72 tand 72 b. FIG. 5D shows a Z-directed component 70D having two wells 73and 75 in addition to conductor 71 and top and bottom traces 72 t, 72 b.The Z-directed component 70E of FIG. 5E has three wells 73, 75 and 76 inaddition to conductor 71 and top and bottom traces 72 t, 72 b. FIG. 5Fshows Z-directed component 70F having two conductors 71 and 77 each withtheir respective top and bottom traces 72 t, 72 b and 78 t, 78 b and nochannels or wells. Z-directed component 70F is a two signal device to beprimarily used for differential signaling. FIG. 5G shows a Z-directedcomponent 70G having one well 73 and two conductors 71 and 77 each withtheir respective top and bottom traces 72 t, 72 b and 78 t, 78 b. FIG.5H shows Z-directed component 70H having one conductor 71 with top andbottom traces 72 t, 72 b and a blind well or partial well 78 extendingfrom the top surface along a portion of the side surface that will allowthe plating material or solder to stop at a given depth. For one skilledin the art, the number of wells and signals is only limited by thespace, required well size and conductor sizes.

In most cases Z-directed components will need to be orientated correctlywhen inserted into a PCB. Accordingly, locating or orienting featuresand connections features may be provided. FIGS. 6A-6C illustrateexamples of such locating features while FIG. 6D illustrate a connectionfeature. In FIG. 6A, Z-directed component 80A has a V-notch 81 on an endsurface extending radially outward. In FIG. 6B, Z-directed component 80Bhas a recess 83 on an end surface of Z-directed component 80B having anorienting surface 84. FIG. 6C shows Z-directed component 80C having aaxial projection, peg 85, extending axially outward from an end surfaceand having an orienting surface 86. An ink mark or other visual ormagnetic indicator on a end surface or on the side of a Z-directedcomponent may also be used to orient a Z-directed component such as whenusing a camera.

As shown in FIG. 6D, Z-directed component 80D may be fitted with aconnection feature such as a conductive pad, a spring loaded stylepogo-pin or even a simple spring 88 that may be used to add anadditional electrical connection (such as frame ground) point to aprinted circuit board. Spring 88 is illustrated as being connected toconductor 89 of Z-directed component 80D.

FIGS. 7A and 7B illustrate another configuration for a Z-directedcomponent utilizing O-rings for use in a PCB having a top and bottomconductive layer and at least one internal conductive layer. Z-directedcomponent 150 is shown having on its top surface 150 t, a locatingfeature 152 and conductive top trace 154 t extending between conductor156 and the edge of body 150 d on its top surface 150 t. (A conductivebottom trace not shown is provided on the bottom surface). Conductor 156extends through a portion of the body 150 d as previously described.Located on the side surface 150 s of body 150 d is a least onesemi-circular channel or grove. As shown a pair of axially spaced apartcircumferential channels 158 a, 158 b are provided having O-rings 160 a,160 b, respectively disposed within channels 158 a, 158 b. A portion ofthe O-rings extend out beyond the side surface 150 s of the body 150 d.O-rings 160 a, 160 b would be positioned adjacent one or more of theinternal layers of the PCB to make electrical contract to one or moretraces provided at that point in the mounting hole for the Z-directedcomponent. Depending on the design an O-ring would not have to beprovided adjacent every internal layer.

O-rings 160 a, 160 b may be conductive or non-conductive depending onthe design of the circuit in which they are used. O-rings 160 a, 160 bpreferably would be compressive helping to secure Z-directed component150 within the mounting hole. The region 162 of body 150 d intermediateO-rings 160 a, 160 b may be comprised of different material than theregions 164 and 166 of the body 150 d outside of the O-rings. Forexample if the material of region 162 is of a resistive material andO-rings 160 a, 160 b are conductive, then internal circuit board tracesin contact with the O-rings see a resistive load.

Regions 164 and 166 may also be comprised of a material having differentproperties from each other and region 162. For example region 164 may beresistive, region 162 capacitive and region 166 inductive. Each of theseregions can be electrically connected to the adjoining layers of thePCB. Further conductor 156 and traces 154 t, 154 b do not need to beprovided. So for the illustrated construction, between the top layer ofthe PCB and the first internal layer from the top, a resistive elementmay be present in region 164, a capacitive element between the firstinternal layer and the second internal layer in region 162 and aninductive element between the second internal layer and the bottom layerof the PCB in region 166. Accordingly, for a signal transmitted from aninternal trace contacting conductive O-ring 160 a and to a secondinternal trace contacting conductive O-ring 160 b, the signal would seean inductive load. The material for regions 162, 164, 166 may haveproperties selected from a group comprising conductive, resistive,magnetic, dielectric, capacitive or semiconductive and combinationsthereof. The design may be extended to circuit boards having fewer ormore internal layers than that described without departing from thespirit of the invention.

In addition regions 162, 164, 166 may have electronic components 167,169, 171 embedded therein and connected as described herein with respectto FIGS. 7-9. Also as illustrated for component 171 a component may befound within one or more regions within the body of a Z-directedcomponent. Internal connections may be provided from embedded componentsto O-rings 160 a, 160 b. Alternatively internal connections may beprovided from the embedded components to plateable pads provided on theside surface 150 s.

The various embodiments discuss for a Z-directed component are meant tobe illustrative and not limiting. A Z-directed component may be made ofa bulk material that performs a network function or may have other partsembedded into its body.

Z-directed Component Examples

Given that a Z-directed component may be a multi-terminal device, it isclear that it may be used to perform, but not limited to, the followingfunctions: transmission line; delay line; T filter; decouplingcapacitor; inductor; common mode choke; resistor; differential pair passthrough; differential ferrite bead; diode; ESD protection devices(varistors). Also note that may combinations by be put together withinone component.

General Z-directed Component Design

FIG. 8 illustrates various configurations for a conductor in aZ-directed component. As shown conductor 90 has a region 92 intermediatethe ends comprising a material having properties selected from a groupcomprising conductive, resistive, magnetic, dielectric, capacitive orsemiconductive properties and combinations thereof. These materials forma variety of components. Additionally a component may be inserted orembedded into region 92 with portions of the conductor extending fromthe terminals of the component. A capacitor 92 a may be provided inregion 92. Similarly a diode 92 b, a transistor 92 c, a mosfet 92 d, azener diode 92 e, an inductor 92 f, a surge suppressor 92 g, a resistor92 h, a diac 92 i and a varactor 92 j and combinations of this items arefurther examples of materials that provided in region 92 of conductor90. While region 92 is shown as being centered within the conductor 90it is not limited to that location.

For multi-terminal devices such as three terminal devices transistor 92c or mosfet 92 d, or integrated circuit 92 k, or a transformer 92 l, oneportion of the conductor may be between the top surface trace and to afirst terminal of the device, the other portion of the conductor betweenthe bottom surface trace and a second terminal of the device. Foradditional device terminals, additional conductors may be provide in thebody of the Z-directed component to allow electrical connection to theremaining terminals or additional conductive traces may be providedwithin the body of the Z-directed component between the additionalterminals and channels on the side surface of the body of a Z-directedcomponent allowing electrical connection to an external conductivetrace. Various connection configurations to a multiple terminal devicemay be used in a Z-directed component.

FIGS. 9 and 10 illustrate two exemplary connection configurations for atransistor. In FIG. 9, a Z-directed component, 100, similar to thatshown in FIG. 5F, having two conductors 102 and 104 in body 105.Conductor 102 comprising a top portion 102 t, a bottom portion 102 b andan intermediate region 102 i wherein transistor 108 is provided. Thebase 108 b of transistor 108 is electrically connected to the topportion 102 t of conductor 102 while the emitter 108 e is connected tothe bottom portion 102 b of conductor 102. The collector 108 c isconnected to conductor 104 via conductive trace 109. In FIG. 10,Z-directed component 110, similar to that shown in FIG. 5C, has body 115including conductor 112 and channel 114. Conductor 112 comprises a topportion 112 t, a bottom portion 112 b, and an intermediate region 112 iwherein transistor 118 is provided. The base 118 b of transistor 118 iselectrically connected to the top portion 112 t of conductor 112 whilethe emitter 118 e is connected to the bottom portion 112 b of conductor112. The collector 118 c is connected by conductive trace 119 to channel114 which is plated. The examples shown in FIGS. 8 and 9 may be extendedto additional channels and conductors allowing for use of multi-terminalcircuits. The connections are intended only to illustrate howconnections to a multi-terminal component may be accomplished and arenot meant to limit how a transistor may be connected within a Z-directedcomponent.

Z-directed Signal Pass-Through Component

Reference is now made to FIGS. 11 and 12 illustrating a Z-directedcomponent termed a signal pass-through that is used for passing a signaltrace from the top surface of a PCB to the bottom surface. FIG. 11 showsa sectional view taken along line 11-11 in FIG. 12 of a PCB 200 having 4conductive planes or layers comprising, from top to bottom, a ground(GND) plane or trace 202, a voltage supply plane Vcc 204, a secondground GND plane 206 and a third ground GND plane or trace 208 separatedby nonconductive material such as a phenolic plastic such as FR4 whichis widely used as is known in the art. PCB 200 may be used for highfrequency signals. The top and bottom ground planes or traces, 202 and208 respectively, on the top and bottom surfaces 212 and 214,respectively, of PCB 200 are connected to conductive traces leading upto Z-directed component 220. A mounting hole 216 having a depth D in anegative Z direction is provided in PCB 200 for the flush mounting ofZ-directed component 220. Here depth D corresponds to the thickness ofPCB 200; however depth D may be less than the thickness of PCB 200creating a blind hole therein. Mounting hole 216, as illustrated, is athrough-hole that is round in cross-section to accommodate Z-directedcomponent 220 but may have cross sections to accommodate the insertionof Z-directed components having other body configurations. In otherwords, mounting holes are sized so that Z-directed components areinsertable therein. For example, a Z-directed component having acylindrical shape may be inserted into a square mounting hole and viceversa. In the cases where Z-directed component does not make a tightfit, resist materials will have to be added to the areas of thecomponent and PCB where copper plating is not desired.

Z-directed component 220 is illustrated as a three lead component thatis flush mounted with respect to both the top surface 212 and bottomsurface 214 of PCB 200. Z-directed component 220 is illustrated ashaving a generally cylindrical body 222 of a length L. A centerconductor or lead 224, illustrated as being cylindrical, is shownextending the length of body 222. Two concave wells or channels 226 and228, that define the other two leads, are provided on the side surfaceof Z-directed component 220 extending the length of body 222. Channels226 and 228 are plated for making electrical connections to Z-directedcomponent 220 from various layers of PCB 200. As shown the ground planetraces on layers 202, 206, and 208 of PCB 100 are electrically connectedto channels 226 and 228. Vcc plane 204 does not connect to Z-directedcomponent 220 as shown by the gap 219 between Vcc plane 204 and wall 217of mounting hole 216.

FIG. 12 illustrates a top view of Z-directed component 220 in PCB 200.Three conductive traces 250, 252 and 254 leading up to the edge of wall217 of mounting hole 216. As illustrated, trace 252 serves as ahigh-frequency signal trace to be passed from the top surface 212 to thebottom surface 214 of PCB 200 via Z-directed component 220. Conductivetraces 250 and 254 serve as ground nets. Center lead or conductor 224 iselectrically connected to trace 252 on the top surface 212 of PCB 200 bya top trace 245 and plating bridge 230. Top trace 245 on the top surfaceof Z-directed component 220 extends from the top end 224 t of conductor224 to the edge of Z-directed component 220. Although not shown, thebottom side of Z-directed component 220 and bottom surface 214 of PCB200 is configured in a similar arrangement of traces as shown on topsurface 212 of PCB 200 illustrated in FIG. 12. A bottom trace on thebottom surface of Z-directed component 220 extends from bottom ofconductor 224 to the edge of Z-directed component 220. A plating bridgeis used to make the electrical connection between the bottom trace andanother high frequency signal trace provide on the bottom surface of PCB200. The transmission line impedance of the Z-directed component can beadjusted to match the PCB trace impedance by controlling the conductorsizes and distances between each conductor which improves the high speedperformance of the PCB.

During the plating process, wells 256 and 258 formed between wall 217 ofmounting hole 216 and channels 226 and 228 allow plating material orsolder pass from the top surface 212 to the bottom surface 214electrically interconnecting traces 250 and 254, respectively tochannels 226 and 228, respectively, of Z-directed component 220 and alsoto similarly situated traces provided on the bottom surface 214 of PCB200 interconnecting ground planes or traces 202, 206 and 208. Theplating is not shown for purposes of illustrating the structure. In thisembodiment Vcc plane 204 does not connect to Z-directed component 220.

One of the challenges for high frequency signal speeds is thereflections and discontinuities due to signal trace transmission lineimpedances changes. Many PCB layouts try to keep high frequency signalson one layer because of these discontinuities caused by the routing ofsignal traces through the PCB. Standard vias through a PCB have to bespaced some distance apart which creates high impedance between thesignal via and the return signal via or ground via. As illustrated inFIGS. 11 and 12, the Z-directed component and the return ground orsignals have a very close and controlled proximity that allowsessentially constant impedance from the top surface 212 to the bottomsurface 214 of PCB 200.

A Z-directed signal pass through component may also comprise adecoupling capacitor that will allow the reference plane of a signal toswitch from a ground plane, designated GND, to a voltage supply plane,designated V_(CC), without having a high frequency discontinuity. FIG.13 shows a cross-sectional view of a typical 4-layer PCB 300 with asignal trace 302 transferring between the top layer 304 and the bottomlayer 306. Z-directed component 310, similar to that shown in FIG. 5D,having body 312 connects signal trace 302 through center conductor 314.Z-directed component 310 also comprises plated channels 316 and 318extending along the side surface 312 s of the body 312. The top 314 tand bottom 314 b of conductor 314 are connected to conductive traces 318t and 318 b on the top 312 t and bottom 312 b of body 312. These in turnare connected to signal trace 302 via top and bottom plating bridges 330t and 330 b. Channels 316 and 318 will be plated to GND plane 332 andVcc plane 334, respectively. Connection points 336 and 338,respectively, illustrate this electrical connection. Schematicallyillustrated decoupling capacitor 350 is internal to body 312 and isconnected between channels 316 and 318. Decoupling capacitor 350 may bea separate capacitor integrated into the body 312 of Z-directedcomponent 310 or it can be formed by fabricating a portion of the body312 of Z-directed component 310 from the required materials withdielectric properties between conductive surfaces.

The path for signal trace 302 is illustrated with diagonal hatching andcan be seen to run from top layer 304 to bottom layer 306. GND plane 332and channel 316 are electrically connected at 336 with the signal pathreturn indicated by the dark stippling 362. Vcc plane 334 and channel318 are electrically connected at 338 with the signal path returnindicated by the light stippling 364 As is known in the art where asignal plane or trace is not to be connected to the inserted part thoseportions are spaced apart from the component as shown at 370. Where asignal plane or trace is to be connected to an inserted component, thesignal plane or trace is provided at the wall or edge of the opening toallow the plating material or solder to bridge therebetween asillustrated at points 330 t, 330 b, 336, and 338.

The vertically hatched portion 380 shows the high speed loop areabetween the signal trace and return current path described by the signaltrace 302 and the GND plane 332 or Vcc plane 334. The signal trace 302on the bottom surface 306 is referenced to power plane Vcc 334 that iscoupled to the GND plane 332 through decoupling capacitor 350. Thiscoupling between the two planes will keep the high frequency impedanceclose to constant for the transition from one return plane to anotherplane of a different DC voltage.

Internally mounting Z-directed components in a PCB greatly facilitatethe PCB technique of using outer ground planes for EMI reduction. Withthis technique, signals are routed on the inner layers as much aspossible. FIG. 14 illustrates one embodiment of this technique. PCB 400is comprised of, from top to bottom, top ground layer 402, internalsignal layer 404, internal signal layer 406 and bottom ground layer 408.Ground layers 402 and 408 are on the top and bottom surfaces 400 t and400 b of PCB 400. A mounting hole 410 shown as a through-hole extendsbetween the top and bottom surfaces 400 t and 400 b. Z-directedcomponent 420 is shown flush mounted in PCB 400. Z-directed component420 comprises body 422 having a center region 424 intermediate the top422 t and bottom 422 b of body 422 and two channels 425 and 427 on sidesurface 422 s.

The channels 425 and 427 and wall 411 of hole 410 form plating wells 413and 415 respectively. Center region 424 is positioned within body 422and extends a distance approximately equal to the distance separatingthe two internal signal layers 404 and 406. Channel 425 extends from thebottom surface 422 b of body 422 to internal signal level 406 whilechannel 427 extends from top surface 422 t of body 422 to internalsignal level 404. Here channels 425 and 427 extend only along a portionof side surface 422 s of body 422. Conductor 426 extends through centerregion 424 but does not extend to the top and bottom surfaces 422 t, 422b of body 422. FIG. 5H illustrates a partial channel similar to channel427. Conductor 426 has conductive traces 428 t and 428 b extending fromthe top 426 t and bottom 426 b of conductor 426 to channels 427 and 425,respectively. While illustrated as separate elements conductor 426 andtraces 428 t, 428 b may be one integrated conductor electricallyinterconnecting channels 425, 427. As shown conductive trace 428 b isconnected to internal signal layer 406 via plated channel 425 and well413 while trace 428 t connects to internal signal level 404 via channel427 and well 415. Ground layers 402 and 408 are not connected toZ-directed component 420 and are spaced away from mounting hole 410 aspreviously described for FIGS. 11 and 13. As shown by double headeddashed arrow 430, a signal on signal layer 406 can be via'd to signallayer 404 (or vice versa) via Z-directed component through a pathextending from well 413, channel 425, trace 428 b, conductor 426, trace428 t, channel 427, and well 415 to allow the signal to remain on theinner layers of PCB 400 with ground layers 402 and 408 providingshielding.

Z-directed Decoupling Capacitors

Capacitors having a Z-directed component body type may be constructed inseveral ways. In FIG. 15 a Z-directed capacitor 500 is shown with body502 having a conductor 504 and two channels 506 and 508 extending itslength similar to those previously described. Conductor 504 is shownconnected to a signal 526. Vertically oriented interleaved partialcylindrical sheets 510, 512 forming the plates of Z-directed capacitor500 are connected to reference voltages such as voltage Vcc and ground(or any other signals requiring capacitance) are used with interveninglayers of dielectric material (not shown). Partial cylindrical sheet 510is connected to plated channel 506 which is connected to Ground 520.Partial cylindrical sheet 512 is connected to plated channel 508 that isshown connected to supply voltage Vcc 522. The sheets 510, 512 may beformed of copper, aluminum or other material with high conductivity. Thematerial between the partial cylindrical sheets is a material withdielectric properties. Only one partial cylindrical sheet is shownconnected to each of Vcc 522 and ground 520, however additional partialcylindrical sheets may be provided to achieve the desiredcapacitance/voltage rating.

Another embodiment of a Z-directed capacitor is shown in FIG. 16 usingstacked support members connected to voltage Vcc or ground. Z-directedcapacitor 600 is comprised of center conductor 601, and a body 605comprised of a top member 605 t, a bottom member 605 b, plurality ofsupport members 610 (illustrated as disks) between the top and bottommembers 605 t, 605 b.

Center conductor 601 extends through openings 615 in the assembledZ-directed capacitor 600 and openings 602 t and 602 b, all of which aresized to closely receive the center conductor. The center conductor iselectrically connectable to conductive traces 603 t and 603 b on the topand bottom portions 605 t, 605 b forming a signal path for signal 626.This connection is made by plating or soldering. Conductor 601 isconnected to signal 626 via conductive trace 603 t. The bottom end ofconductor 601 is connected in a similar fashion to a signal trace (notshown) via conductive trace 603 b.

Opposed openings 607 t and 608 t are provided at the edge on top portion605 t. Bottom portion 607 is of similar construction as top portion 605having opposed openings 607 b and 608 b provided at the edge. Betweentop and bottom portions 605, 609 are a plurality of support members 610,which provide the capacitive feature. Support members 610 each have atleast one opening 613 at their outer edge and an inner hole 615 allowingfor passage of conductor 602 therethrough. As shown two opposed openings613 are provided in each support member 610. When assembled the opposedopenings 607 t, 607 b, 608 t, 608 b, and 613 align to form opposedchannels 604 and 608 extending along the side surface of Z-directedcapacitor 600. Channel 604 is shown connected to reference voltage suchas ground 620 and channel 606 to another reference voltage such as Vcc622. Support members 610 may be fabricated from a dielectric materialand may be all of the same or varying thickness allowing for choice indesigning the desired properties for Z-directed capacitor 600.

Annular plating 617 is provided on one of top and bottom surfaces ofsupport member 610 or if desired on both surfaces. As shown annularplating is shown on the top surface of each support member but locationof the annular plating can vary from support member to support member.Annular plating 617 generally conforms to the shape of the supportmember and extends from one of the edge opening 613 toward the other ifan additional opening is provided. The annular plate 617 is of adiameter or dimension or overall size that is less than the diameter,dimension or overall size of support member 610 on which it is affixed.While the plate 617 is described as annular, other shapes may also beused provided that the plating does not contact the center conductor orextend to the edge of the support member on which it is plated orotherwise affixed. The annular plate does contact one of the edgeopenings 613 but is spaced apart from the other openings, if more thanone channel is present in the side surface of the body of Z-directedcapacitor 600. Also there is an opening 619 in annular plate 617 havinga larger diameter than opening 615 in annular plate 617 through whichconductor 601 passes. Opening 619 has a larger diameter than that ofconductor 602 leaving annular plate 617 spaced apart from conductor 602.

As illustrated the support members 610 are substantially identicalexcept that when stacked alternate members are rotated 180 degrees withrespect to the member above or below it. This may be referred to as a1-1 configuration. In this way, alternate members will be connected toone or the other of the two channels. As shown in FIG. 16, the annularplating on the upper one of the two support members 610 is connected tochannel 608 and voltage Vcc 622 while the annular plating on the lowerone of the two support members 610 is connected to channel 604 andground 620. Other support member arrangements may also be used such ashaving two adjacent members connected to the same channel with the nextsupport member being connected to the opposite channel which may bereferred to as a 2-1 configuration. Other configurations may include2-2, 3-1 and are a matter of design choice. The desired capacitance orvoltage rating determines the number of support members that areinserted between top and bottom portions 605, 609. Although not shown,dielectric members comprised of dielectric material and similarly shapedto support members 610 may be interleaved with support members 610.Based on design choice only a single channel may be used or morechannels may be provided, the annular plating may be brought intocontact with the center conductor and not in contact with the channels.Again the embodiments for Z-directed capacitors are for purposes ofillustration and are not meant to be limiting.

With either design for a Z-directed capacitor, a second conductor may beprovided in parallel with the first conductor that is disposed withinthe conductive plates to create a differential decoupling capacitor.Another embodiment of a Z-directed capacitor can be constructed fromFIG. 15 or FIG. 16 by connecting center conductor to one of thereference voltages at each support member that also has its annularplating connected to the same reference voltage. This may beaccomplished simply by connecting the conductor to the annular platingas schematically illustrated by the jumper 621. In practice the annularopening 619 in the annular plate 617 would be sized so that the annularplate and conductor 602 would be electrically connected. This componentmay be place directly below a power pin or ball of an integrated circuitor other surface mounted component for optimum decoupling placement.

Z-directed Signal Delay Line

FIGS. 17A-17C and 18 illustrate embodiments of Z-directed signal delayline component. In general a Z-directed signal delay line comprises abody having a signal conductor routed therein with the signal conductormade from one of a dielectric material, and a magnetic material thatslows down signals that travel through the delay line. The signalconductor has a length contained within the body and may be of the samelength as the length of the body or may be longer in length than thelength of the body. Connections to the signal conductor may be made viachannels provided on the side surface of the Z-directed component or toconductive traces provided on the top and or bottom surfaces or by acombination of top and/bottom traces and channels. In FIG. 17A,Z-directed component 700A has a body 702 having conductive traces 703 aand 703 b on its top surface 702 t. Disposed within body 702 a is delayline 704 comprised of a plurality of conductive legs comprisingvertically oriented segments 704 a-704 d extending along a portion ofthe length of body 702 a and connected by a plurality short horizontalbars 704 e in a serial fashion at their respective top and bottom ends(roughly approximating a W-shape) forming the delay line 704 in anundulating or a zigzag manner. The top ends of segments 704 a and 704 d(the start and end of the conductor forming the delay line) are shownconnected to conductive traces 703 a and 703 b respectively on the topsurface 702 t of the body 702 a. The additional length of the conductorforming delay line 704 inserted into a signal path causes the signaltravel a longer distance therefore delaying it. The connection to delayline 704 may also be accomplished using a channel provided in the side702 s of body 702 a either in combination with conductive traces on thetop or bottom surfaces or in lieu of top and bottom conductive traces.Additional segments may be added to delay line 704 to increase theamount of delay.

In FIG. 17B, a Z-directed component delay line 700B has a body 702 withconductive traces 703 t and 703 b on the top and bottom of body 702 b.Within body 702 b is delay line 705 comprised of a plurality ofhorizontally disposed (as viewed in FIG. 16B) C-shaped conductors 705a-705 d spaced apart from one another and serially connected by aplurality vertical leg segments 705 e. The C-shaped conductors 705 a-705d may also be described as being disposed approximately parallel to thetop or bottom surfaces, 702 t, 702 b of the body 702 and the legsegments 705 as approximately parallel to the side surface of the body.The ends of leg segments 705 e adjacent the top and bottom of body 702 bconnect to traces 703 c and 703 d on the top and bottom surfaces. Againthe additional length of delay line 705 inserted into a signal pathcauses the signal travel longer, delaying it. If there is excessivecapacitive coupling between adjacent C-shaped conductors then ashielding material (not shown) may be disposed within body 702 betweenadjacent C shaped conductors and grounded. It is expected that thisshould remove most of the parasitic affects of this geometry. Theconnections between adjacent C-shaped conductors are made such that themagnetic flux of one C-shaped conductor cancels the next. This reducesthe magnetic coupling between the C-shaped conductors. AdditionalC-shaped conductors may be added to increase the delay. Alternatively,the delay line may be arranged in a spiral configuration.

FIG. 17C illustrates a programmable version of the Z-directed delay lineof FIG. 17B. Z-directed delay 700C has body 702 b having top and bottomtraces 703 t. Delay line 705 disposed within body 702 b is comprised ofa plurality of serially connected C-shaped conductors as previouslydescribed. A shorting mechanism for the C-shaped conductors is disposedwithin or on the body 702 b and may be comprised of at least oneshorting bar. By selectably removing portions of the shorting barbetween adjacent C-shaped conductor the amount of delay provided byZ-directed component delay line 700C may be adjusted or programmed. Asillustrated two drillable shorting bars 708, 709 are shown and used toprogram the delay time of the part. In this embodiment shorting bars708, 709 extend along the length of the body 702 b and tangentiallycontact each of the C-shaped conductors. The shorting bars 708 and 709are diametrically opposed to one another such that a line drawn betweenthem would bisect each C-shaped conductor 705 a-705 d. If the minimumdelay is desired then shorting bars 708, 709 are left in place. If themaximum delay is desired then shorting bars 708, 709 are removed bydrilling or etching the conductive material away. As portions ofshorting bars 708, 709 are removed between adjacent C-shaped conductors,the time delay will increase by ½ or whole turn increments at time. Thiscan be used in development to easily determine the best signal delay forproduction purposes. Also each PCB may be tuned during functionaltesting to optimize the delay of signals to compensate for variation ofother parameters in a design.

One or more shorting bars may also be used with Z-directed delay line700A by placing the shorting bar horizontally across the verticalconductor segments 704 a-704 d as indicated by the line 710. Howeverwith this design the time delay would have to be adjusted prior toinsertion of the part into a PCB. In yet another embodiment, one or morechannels may be provided as a shorting mechanism in lieu of shortingbars and by use of selective plating techniques in plating suchZ-directed delay lines portions of delay lines 704 or 705 may be shortedtogether.

In FIG. 18 a variable delay line 730 may be created by connecting anynumber of Z-directed delay line together by conductive traces on a PCB.These surfaces are shown as transparent to illustrate the connections.Inserted in PCB 740 are cylinders 750, 760, and 770 which can representeither a Z-directed delay line, as illustrated in FIGS. 17A-17C, or aconductive plug or Z-directed signal pass through component and whichare connected in series fashion by top and bottom conductive traces 780t, 780 b as shown on the top and bottom surfaces 740 t, 740 b of PCB740. Cylinders 750, 760 and 770 may also be connected serially viaconductive traces provided on internal layers of PCB 740 if present orby a combination of internal or external conductive traces. If cylinders750, 760 and 770 each represent a Z-directed delay line element, thentotal delay across delay line 730 may be changed by replacing aZ-directed component delay line elements with a Z-directed componentsignal pass through device, previously described, that introduces nosignificant delay or with another Z-directed component delay line havinga greater delay. One advantage of this configuration is that no changesare required to the PCB layout design while still allowing the totalsignal delay to be adjusted.

Z-directed T-Filter/PI Filter

A Z-directed T filter and a Z-directed Pi filter are three port deviceshaving an input conductor, output conductor and a ground conductor. Tfilters are generally comprised of, for a low pass filter, two serialresistors connected between an input and an output with a capacitorconnected between the resistors and to ground or, for a high passfilter, two serial capacitors connected between the input and an outputand a resistor connected between the capacitors and to ground.Schematically these filter resemble the letter T. Pi filters have onecomponent connected between input and output with a second componentconnected between input and ground and a third component connectedbetween the output and ground. The first component may be a resistor andthe second and third component may be capacitors and vice versa.Inductors may also be used. These devices may be mounted in a Z-directedcomponent in a similar fashion as the transistor shown FIGS. 8 and 9.

Z-directed Ferrite Bead

FIGS. 19A-19C illustrate cross-sectional views of alternate embodimentsof Z-directed ferrite beads. The construction of these devices issimilar to that shown and described in FIGS. 5B-5H. Disposed, as shownin FIG. 19A, in a portion of the body 1000 is a cylinder 1001 ofmagnetic material having an opening through which conductor 1002 passes.The conductor 1002 extends to the top and bottom surfaces of the body1000 where it is electrically connected to top and bottom traces. Theconductor may also be connected as previously described such as to achannel on the side surface of the body or two side channels etc. Byvarying the outside diameter cylinder 1001 the magnetic properties arevaried controlling the characteristics of the ferrite bead. As showncylinder 1001 is contained within body 1000 but its outer circumferencemay also extend to the side surface of body 1000. This constructioncreates a single conductor differential Z-directed ferrite bead.

In FIG. 19 b two conductors 1002-1 and 1002-2 pass through two openingsprovided in cylinder 1001 in the body 1000 forming a two conductordifferential mode Z-directed ferrite bead. The two parallel spaced apartconductors 1002-1 and 1002-2 are enclosed by cylinder 1001 comprised ofmagnetic material. By varying the outside diameter cylinder 1001 themagnetic properties are varied controlling the characteristics of theferrite bead. As shown cylinder 1001 is contained within body 1000 butits outer circumference may also extend to the side surface of body1000.

Shown in FIG. 19C, is a two conductor common mode Z-directed ferritebead that is substantially similar to a two conductor differential modeZ-directed ferrite bead but with both of the conductors 1002-1, 1002-2within the cylinder 1001 a passing through a common opening 1003 in themagnetic material forming cylinder 1001 a. The volume within opening1003 is not filled with magnetic material. The volume may be left empty,i.e. air filled, or another nonmagnetic material may be used to filledthe portion not filled by conductors 1002-1, 1002-2.

Z-directed Switch

The Z-directed component acting a single pole single position, or amulti-pole multi position switch may be used to program differentsettings into a PCB by rotating it to different positions about its axisof insertion. FIGS. 20A and 20B illustrate a PCB 1101 having amultiplicity of internal layers 1102 having one or more conductivetraces and a multiplicity of conductive surface traces 1103, three ofwhich are further designated as a, b and c, on outer surface 1104.Conductive traces may be provided on both outer surfaces of PCB 1101. InFIG. 20A, Z-directed component 1105 is mounted in mounting hole 1106shown as a through hole. A channel 1107 of Z-directed component 1105 isshown aligned with circuit trace 1103 a. The channel 1107 extends alongthe side surface 1105 from the top surface 1105 t to bottom surface 1105b. However the length of the channel may be less the length of the bodyof the Z-directed component and may extend only from one of the top andbottom surfaces toward the other or may be disposed intermediate the topand bottom surfaces such as, for example, extending only between the twointernal layers of PCB. Shown inserted into channel 1107 is acompressive conductive member, such as rod 1109. Provided in top surface1105 t of Z-directed component 1105 is turning structure, such as slot1108 used to rotate Z-directed component 1105 into alignment with thedesired surface trace 1103. Other configurations such as a pair of holesor a cross-shaped slots may also be used in lieu of slot 1108.

Referring now to FIG. 20B which is a sectional view taken along line20B-20B of FIG. 20A with Z-directed component 1105 removed, amultiplicity of internal connection points 1110-1113 are shown. Withcompressive conductive member 1109 of Z-directed component 1105 alignedwith trace 1103 a, connection between trace 1103 a and connection point1110 is made as indicated by the dashed line interconnecting these twopoints. If compressive conductive member 1109 of Z-directed component1105 is aligned with trace 1103 b, then trace 1103 b will be connectedto connection point 1111 as indicated by the dashed line interconnectingthese two points. Similarly if compressive conductive member 1109 ofZ-directed component 1105 is aligned with trace 1103 c, then trace 1103c will be connected to connection points 1112 and 1113 as indicated bythe dashed line shown interconnecting these three points.

When the compressive conductive member is a rod it may have a diameterthat is less than and preferably equal to or greater than the diameterof channel 1107. In FIGS. 20C and 20D, compressive conductive rod 1109is shown having a diameter that is larger than the diameter of channel1107. This is done to ensure that compressive rod 1109 will becompressed when inserted in channel 1107 helping to ensure thatcompressive conductive rod 1109 will be retained within the body ofZ-directed component 1105 due to the interference fit between the rodand channel. Further, as illustrated in FIG. 20D, channel 1107 ispositioned at the edge of Z-directed component 1105 so that the centerline 1109 a of compressive conductive rod 1109 will positioned at adistance that is within or less than the radius R of Z-directedcomponent 1105 while still allowing a strip 1109 s of the outer sidesurface of compressive conductive rod 1109 to extend beyond the sidesurface 1105 s of Z-directed component 1105 to make the desiredelectrical connections. This strip or portion 1109 s of the outerperiphery is exaggeratedly shown in FIG. 20D. It is expected that thiswill also aid in keeping Z-directed component 1105 inserted into PCB1101. Additional channels and compressive conductive rods may also beprovided in Z-directed component 1105 and arranged about the peripheryof Z-directed component 1105 as needed to meet the design requirementsfor the circuit forming a multi-pole switch.

It will be realized that if diameter of compressive conductive rod 1109is equal to or less than the diameter of the channel 1107 and thecenterline of the compress conductive rod is at or beyond the sidesurface of the body of Z-directed component 1105, the rod will tend tofall out of the channel. Some means such as an adhesive on the portionof the compressive conduct rod within the channel or on the surface ofthe channel will need to be used to retain the rod 1109 in channel 1107when inserted therein prior to the insertion of Z-directed component1105 into PCB 1104. With compressive rod 1109 having a diameter that isless than the diameter of channel 1107 shims or other means such asraised portions in the channel wall inserted between the channel surfaceand the compressive conductive rod may be used to ensure the compressiveconductive rod will have a portion extending beyond the side surface1105 s of Z-directed component 1105.

In general, the channel shape and the compressive conductive membershape should correspond to one another so that the rod will be held bythe channel when it is inserted therein while still allowing a portionof the compressive member to extend beyond the side wall of theZ-directed component. While cylindrical channels and rods are describedit is understood that other shapes may also be used. For example, asshown in FIG. 20D, channel 1120 is generally triangular or trapezoidalin section with the open apex aligned with the side surface. Showninserted in channel 1120 is a generally rectangular compressiveconductive member 1122 which has pinched-in waist 1122 w caused by thesectional shape of channel 1120. Member 1122 may also have a triangularsection as well.

Use of Z-directed component 1105 in this manner allows PCB 1101 to beconfigured with an identification indicia such as a serial number usinga minimal number of components. Connections between the surface layersof PCB 1101 (either top surface, bottom surface or both) can also bemade to inner layers by the use of a well provided in Z-directedcomponent 1105 as previously described. Further one or more wells andone or more center conductors may be used to provide for a multiplicityof connections between and among the internal layers 1102 and surfacelayers of PCB 1101. Although it is contemplated that once Z-directedcomponent 1105 is positioned and aligned with the desired traces itwould be plated in place, Z-directed component 1105 may also beremovably inserted into mounting hole 1106 allowing for it to berealigned similar to a single-gang or multi-gang rotary switch,depending on the number of layers in PCB 1101. A slot may be provided inone of the end surfaces of Z-directed component to allow it to berotated by a screwdriver or other similar means. To hold Z-directedcomponent in the mounting hole while still allowing for rotation,compliant strips or other similar means may be provided on thecircumferential surface of the Z-directed component When the mountinghole is a through hole, the top surface 1105 t may have radialprojections 1130 or a flange that can be used to prevent the Z-directedcomponent from sliding out of the mounting hole when being rotated.

Building upon a Z-directed switch, the Z-directed component 1105 mayhave a number of different circuits or values of components, indicatedby dashed block 1115 in FIG. 20C, incorporated into the body thereof andbe used to connect one or more traces on a layer of the PCB (interior orexterior layer) with another one of more traces on the same or othersurfaces in the PCB using channels or conductors as previouslydescribed. By having multiple paths through a Z-directed componentdifferent circuits can be selected by rotating the part to select whichconductor(s) is/are bridged that have the desired circuit componentbetween 2 or more connection points. For example one Z-directedcomponent may have a range of resistive values therein that are selectedby inserting the Z-directed component and aligning it with the desiredconductive traces. The concept may be expanded to any combination ofelectronic components that will fit within the volume of the body of theZ-directed component along with the necessary conductive traces.

Z-directed Internal Connector

One of the problems with very high speed signals is that transitioningbetween PCB layers requires a via hole to make the transition. The viacopper has a significant surface area as compared to the signal. Thiscauses a transmission line discontinuity that may affect the signalquality. Current high speed PCB designs sometimes require these vias tobe back drilled to reduce the surface area of the via. An example wouldbe when a signal transitions between two inner layers then the outersegments of the via may need to be removed. A drill bit is used toremove the copper between the surfaces of the PCB down to the area thatthe signal is located in the PCB. FIGS. 21A, 21C, and 21D illustrateanother configuration of an internal Z-directed component connector thatcan make the internal connections without the need for this backdrilling process. This embodiment also illustrates the use of test pathswith the body of the Z-directed component. This interior connector maybe used anytime a plating well is not desired to the top or bottomlayers of a PCB.

In this embodiment a Z-directed component 1200 has at least two recessedareas or pockets 1202 a, 1202 b, 1202 c, 1202 d on the side surface 1200s that will contain a solder paste material (not shown) that will eitherexpand or reflow when heated to make the desired connections. Aconductor 1216 a, 1216 b, 1216 c, 1216 d is provided between top surface1200 t and each of pockets 1202 a-1210 d, respectively. The portions1216 a 1-1216 d 1 of conductors 1216 a-1216 d on surface 1200 t may beused as test points by test probes as described herein.

Shown in the FIG. 21B is a sectional view of a four-layer PCB 1210having two internal layers 1211 a, 1211 b, each having two conductivesignal traces 1212 a and 1212 b, 1212 c and 1212 d, respectively,provided at four internal locations in the wall 1214 w of mounting hole1214. For purposes of illustration only, it is desired to interconnecttrace 1212 a to trace 1212 c and trace 1212 b to trace 1212 d. Othernumbers of internal layers and signal traces may also be connected in asimilar fashion using an appropriately designed Z-directed componentinternal connector. In Z-directed component 1200 four correspondinglypositioned pockets 1202 a-1202 d are positioned on side surface 1200 sso that when Z-directed component 1200 is inserted into mounting hole1214 these pockets will be adjacent to traces 1212 a-1212 d respectivelyon internal layers 1211 a, 1211 b.

The pockets may be interconnected by a variety of means as is known inthe art. Two examples are illustrated in FIGS. 21A and 21C. One is achannel 1220 cut into side surface 1200 s interconnecting pockets 1202 band 1202 d that may be filled with solder paste or into which the solderpaste in the pockets will flow when heating of the PCB occurs.Additional channels interconnecting all of the pockets together can beprovided and the pockets may be selectably interconnected by use ofremovable dams indicated by dashed lines 1224 provided in the channel1220. This permits the interconnections to be determined after theZ-directed connector has been fabricated. Where a connection is desiredbetween two pockets the dam 1224 in the channel interconnecting thesepockets would be removed. The other connection may be done by aconductor 1222 provided in the body 1200 b interconnecting pockets 1202a and 1202 c. With this arrangement the manner of the interconnectionwould need to be predetermined so that the conductors are positionedbetween the desired interconnection points.

Once the Z-directed component 1200 is soldered in place the internalconnections can be checked by test probes placed on test points 1216 a1-1216 d 1. For the illustrated pairs of connections only a single testpoint is needed for each pair of interconnected pockets; however it maybe desired to have a test point for each connection pocket as shown.

FIGS. 21C and 21D show Z-directed component internal connect 1200 havingan optional multi-terminal component 1230 either embedded or formedwithin the body 1200 b. Component 1230 may be an active or passivecomponent may also be inserted in the connection path to the internallayers 1211 a , 1211 b of PCB 1210. As shown one terminal of component1230 is connected to top surface 1200 t of Z-directed component 1200 viaconductor 1232, a second terminal is shown connected to pocket 1202 avia conductor 1234 and a third terminal of component 1230 is shownconnected to pocket 1202 d via conductor 1236. Components having more orless terminals may also be accommodated within Z-directed component 1200depending on volume available for the internal component and conductors.

The test paths 1216 a-1216 d may not be present in some designs.However, the testing paths may be used with any of the Z-directed partsdescribed herein to improve testability. Also the top and or bottomsurface of this Z-directed component may have a conductive coatingsubstantially coextensive with the surface to provide further shieldingwhen the Z-directed component is installed and plated in a PCB.

In some cases depending on the desired function, a Z-directed componentmay work best when partially inserted into the PCB and/or allows thevalue of the Z-directed component to be varied. A Z-directed componentmay have a parameter, such as resistivity that can be controlled orvaried by the depth that it is inserted into the PCB. One example wouldbe a resistor that normally has a fixed resistive value between the topand bottom surfaces by applying a uniform resistive film over the sidesurface of the body. This is illustrated in FIGS. 22A and 22Billustrating a PCB 1300 having a Z-directed resistor 1320 inserted attwo different depths into a mounting hole 1302 indicated by the dashedlines. The PCB 1300 is illustrated as having signal traces 1303, 1305 onone external surface, top surface 1300 t and signal traces 1307, 1309 onthe other external surface, bottom surface 1300 b. As shown in bothfigures Z-directed resistor 1320 interconnects signal trace 1303 tosignal trace 1305. Two internal layers are shown for PCB 1300, a firstvoltage reference layer Vcc 1311, and a second voltage reference layerGND 1313. Side surface 1330 s of body 1330 has two closed end or blindchannels, 1332, 1334 extending from top surface 1330 t. These blindchannels could also both extend from the bottom surface 1330 b. Aplateable strip 1340 is shown disposed on side surface 1330 s of body1330 between the top and bottom surfaces 1330 t, 1330 b. Disposed withinbody 1330 are conductors 1335, 1336 electrically connected to respectiveends of plateable strip 1340. The other ends of conductors 1335, 1336are electrically connected to channels 1332, 1334. Line 1350 indicatesthe position of top surface 1300 t with respect to body 1330. Z-directedresistor 1320 is inserted into mounting hole 1302 a depth D1 whereportion P1 represent the portion of plateable strip 1340 below the topsurface 1300 t of PCB 1300 and portion P2 represents the portion ofplateable strip 1340 above. When the circuit board 1300 is plated theexposed side surface 1300 s above the top surface 1300 t along withportion P2 of plateable strip 1340 would be plated with copper shortingout the portion P2 and reducing the overall resistance of Z-directedresistor 1320. The channels 1332, 1334 are closed ended to prevent theplating material from shorting the two channels together. In FIG. 22B,Z-directed resistor is shown inserted at a greater depth D2. Accordinglyon plateable strip 1340 portion P1 has increased and portion P2 hasdecreased. At insertion depth D2 and after plating has occurred, theoverall resistive value of Z-directed resistor 1320 is greater than thatwhen inserted at depth D1.

This concept may be used with any passive element that can have itsvalue adjusted by plating over part of a surface. One example is aZ-directed inductor wherein portions of the windings are exposed alongthe length of the side surface, Another example is a Z-directedcapacitor having stacked disks similar to those as shown in FIG. 15 butmodified so as not to have the annular plate 617 connected to either ofthe side channels 604, 608. Instead one or more of the annular plates617 would be electrically connected to a corresponding conductordisposed within the body 605 with the other end of the conductor beingexposed on the side surface of the body 605. A further example is asignal delay line such as that shown in FIG. 17B having a portion ofC-shaped conductors 705 a-705 d exposed in the side surface 702 bs.Another use for this partial insertion technique would be wheredifferent electronic functions exist in regions between the top andbottom surfaces of the body of the Z-directed component. As shown inFIG. 7B multiple devices or circuits may be provided in the body 150.Internal connections may be provided to plateable pads provided in theside surface. The exposed pads would be shorted out by the copperplating in a similar way to the resistor example. As discussed later, aZ-directed component can be adjusted after the PCB has beenmanufactured. A circuit design may call for a Z-directed componentproviding an optional function or feature to the circuit to be partiallyinserted into the PCB and make no connections at the time ofmanufacturing. Later if the Z-directed component is needed to add itsnew function to the circuit in the PCB it would be pushed into placewhile in the field.

In another embodiment the strip used in a Z-directed variable valuecomponent may also have one or more etchable portions 1360 having aconductor connected to each end of the strip (see FIG. 22A). Theconductors may be internal to the body of the component, provided on anexternal surface or be a combination of external and internal connectsas previously shown and described. The value of the Z-directed variablevalue component would be adjusted by selectively etching away etchableportions 1360 of the strip while still maintaining a signal path betweenthe two end conductors. For example, if the strip were comprised of aresistive material, removal of some of this material by etching woulddecrease the value of the resistance. Depending on the material withinthe etchable portions the value of the component may increase ordecrease as the material is etched away. Depending on the depth to whichsuch a component is mounted in the PCB, fewer or more of the etchableportions would be exposed to etching.

Installation of Z-directed Components in a PCB

Given the shape and intended placement of a Z-directed component to bewithin a recess or through-hole in a PCB one way of achieving thisplacement is by use of an insertion system 800 comprising an orientingfixture 802 and ram plate 804 as shown in FIG. 23. Positioned onorienting fixture 802 are one or more Z-directed components 806.Orienting fixture 802 using locating surfaces or other indicia providedon Z-directed components 806 ram plate orients these components forinsertion into PCB 850 shown positioned over orienting fixture 802 andhaving one or more mounting holes 852 for receiving Z-directed component806 therein as previously described. PCB 850 is held by a fixture notshown. As shown mounting holes 852 are through-holes and the depth D ofthe holes corresponds to the length L of Z-directed components 806. Aspreviously described the length L may be less than, equal to or greaterthan depth D allowing for recessed mounting, flush mounting or extendedmounting. For recessed Z-directed components, resist material will beneeded to ensure that only those portions of the recessed surface thatare to be plated will be plated and to avoid plating of the entirerecessed surface.

Ram plate 804 is raised as indicated by arrow 860 inserting Z-directedcomponents 806 into corresponding mounting holes 852 in PCB 850 throughthe bottom surface of PCB 850. The ram plate may have cylinders thatpress each component 806 through the orienting fixture 802 into mountingholes 852 to the correct depth. These cylinders may be individuallyoperated or any combination at one time.

To facilitate use of a Z-directed component, insertion equipment thatorientates the part and inserts them into the PCB will be needed.Although not shown it should be realized that pick and place equipmentmay also be used to insert a Z-directed component into a PCB. Such pickand place equipment may insert a Z-directed component from either thetop or bottom surface of a PCB. A plunger device will be needed to pressthe Z-directed component into the PCB to the desired insertion depth.

Z-directed components may be press fit or glued in place in a PCB. ThePCB and Z-directed component interface can include resist material toprohibit plating or seed material to help facilitate plating. Examplesare shown in FIGS. 24 and 25. In FIG. 24 a Z-directed component 900having a body 902 and two channels 904 a and 904 b extending along sidesurface 902 s and a conductive top trace 906 is shown having a gluestrip 910 or a glue dot 911 on side surface 902 s allowing Z-directedcomponent 900 to adhere to the wall of a mounting hole in a PCB prior toplating. In FIG. 25 a Z-directed component 920 having a body 922 and twochannels 924 a and 924 b extending along side surface 920 s and aconductive top trace 926 is shown having copper seed material 927indicated by the horizontal lines on channels 924 a, 924 b conductivetrace 926 with resist material 928 indicated by the angled lines on theremaining portions of side surface 902 s. Compliant materials may beused to keep plating material from migrating past desired locations. Forparts that extend past the surface of the PCB, the seed copper may betaken around the edge of a Z-directed component down the side surface tothe surface of the PCB.

Other surface mount parts may be mounted over the part and may even havepads or balls to have surface mount parts connected directly to them.For example, for ball gate array devices, the balls may be attacheddirectly to the top surface of a Z-directed component. Z-directedcomponents may also be contained in a tape and reel packaging material.A part can be extracted using a pick and place vacuum head and bepartially inserted in to a PCB. A camera can then be used to check theorientation of the Z-directed component and the Z-directed componentposition adjusted before being fully inserted into the PCB.

The foregoing description of several embodiments of the invention hasbeen presented for purposes of illustration. It is not intended to beexhaustive or to limit the invention to the precise forms disclosed, andobviously many modifications and variations are possible in light of theabove teaching. It is intended that the scope of the invention bedefined by the claims appended hereto.

1. A Z-directed component for mounting in a printed circuit board (PCB)having a mounting hole having a depth D therein and a plurality ofconductive traces, the Z-directed component comprising: an insulativebody of a length L comprising: a top surface; a bottom surface; a sidesurface between the top and bottom surfaces; a cross-sectional shapethat is insertable into the mounting hole in the PCB; and a first and asecond electrically conductive channels on the side surface with thefirst channel and second channel both extending from one of the top andbottom surfaces; a plateable strip disposed on the side surfaceintermediate the top and bottom surfaces; and a first and secondconductor disposed within the body, the first conductor electricallyconnected to the first channel and one end of the plateable strip andthe second conductor electrically connected to the second channel andthe other end of the plateable strip.
 2. The Z-directed component ofclaim 1 wherein the plateable strip is comprised of a resistivematerial.
 3. The Z-directed component of claim 1 wherein the plateablestrip is comprised of a material having an electrical characteristicthat changes when plating is applied to the strip after installation ofthe Z-directed component in the mounting hole of the PCB.
 4. AZ-directed component for mounting in a printed circuit board (PCB)having a mounting hole having a depth D therein and a plurality ofconductive traces, the Z-directed component comprising: an insulativebody of a length L comprising: a top surface; a bottom surface; a sidesurface between the top and bottom surfaces; a cross-sectional shapethat is insertable into the mounting hole in the PCB; and a first and asecond electrically conductive channels on the side surface with thefirst channel and second channel both extending from one of the top andbottom surfaces; a strip disposed on the side surface intermediate thetop and bottom surfaces having at least one etchable portion therein;and a first and second conductor disposed within the body, the firstconductor electrically connected to the first channel and one end of thestrip and the second conductor electrically connected to the secondchannel and the other end of the strip.
 5. The Z-directed component ofclaim 1 wherein the at least one etchable portion is comprised of aresistive material.
 6. The Z-directed component of claim 1 wherein theat least one etchable portion is comprised of a material having anelectrical characteristic that changes when etching is applied to thestrip after installation of the Z-directed component in the mountinghole of the PCB.